Obsession depression
When you're so deep in the weeds of something you can't see straight and once you get it, you're just left high and dry with nothing but a bad taste in your mouth and a headache.
I got the job I wanted for 3 years, and now I just wanna die.
She finally got the guy, but he turned out to be a total dud.
He spent 6 months planning the perfect pizza, and it was just cheese and bread.